There is nothing to block sunlight in cosmic space and thus an enormous amount of solar energy is applied to surfaces of equipment used in the cosmic space, such as artificial satellites and space stations (hereinafter referred to as artificial satellites and the like). On the other hand, since precise machines are installed inside the artificial satellite, it is necessary to maintain the inside in an allowable temperature range.
The present applicant has marketed a thermal control material for use in outer space (UTC series) provided by evaporating aluminum or the like onto polyimide film known as UPILEX® (polyimide; registered trademark). However, to suppress an increase in temperature of the artificial satellite caused by sunlight and to dissipate heat generated inside, it is still desirable to develop an excellent material having an extremely low absorptance of sunlight (αs) and a high thermal emittance (∈H).